The following is an example of a batch body.
example body
{
  "batch": [
    {
      "type": "track",
      "event": "Signed Up",
      "userId": "1043",
      "properties": {
        "plan": "Enterprise"
      },
      "messageId": "1ff51c9c-4929-45de-8914-3bb878be8c4a"
    },
    {
      "type": "identify",
      "userId": "532",
      "traits": {
        "email": "john@email.com"
      },
      "messageId": "6f5f436d-8534-4070-8023-d18f8b78ed39"
    }
  ]
}